The present invention relates to an actuating system for a variable area exhaust nozzle, particularly such a system which utilizes a single actuating cylinder to vary the positions of inner and outer nozzle flaps.
It is known to equip gas turbine engines, such as those utilized in jet powered aircraft, with exhaust nozzles having inner and outer flaps whose positions may be varied to vary the performance characteristics of the aircraft. The flaps may be actuated by one or more control cylinders to vary their positions.
British Patent 1 254 175 discloses an exhaust nozzle comprising inner flaps controlled by two distinct sets of control cylinders and outer flaps controlled by a third set of control cylinders, different from the first two sets of control cylinders. While this system operates well, it has the drawbacks of substantial cost, as well as substantial weight and bulk due to the use of three distinct sets of control cylinders.
U.S. Pat. No. 3,537,647 discloses a variable area nozzle which reduces the weight, cost and bulk over the previously discussed system by providing for control of both the inner and outer flaps by single set of control cylinders. However, this system cannot provide some of the desirable adjustments for the flaps and thereby precludes optimizing the exhaust nozzle operation, particularly when associated with a gas turbine engine used in an aircraft which may fly at supersonic speeds.